Radiologically, lung fields are divided into 3
ZONES……
UPPER ZONE - From above upto 2
nd
costal
cartilage
MIDDLE ZONE - 2
ND
TO 4
TH
Costal cartilage
LOWER ZONE - Below 4
th
costal cartilage
Patient particulars
View- Pa / AP / Lateral / Oblique
Should see ribs through
the heart
Barely see the spine
through the heart
Should see pulmonary
vessels nearly to the
edges of the lungs
OVERPENETRAT
ED FILM
• Lung fields darker
than normal—may
obscure subtle
pathologies
• See spine well beyond
the diaphragms
• Inadequate lung detail
Underpenetrated
Film
•Hemidiaphragms
are obscured
•Pulmonary
markings more
prominent than they
actually are
Should be able to
count 9-10
posterior ribs
Heart shadow
should not be
hidden by the
diaphragm
1
2
3
4
5
6
7
8
9
10
Medial ends of
bilateral clavicles
are equidistant from
the midline or
vertebral bodies
If spinous process appears closer to the right clavicle (red
arrow), the patient is rotated toward their own left side
If spinous process appears closer to the left clavicle (red arrow),
the patient is rotated toward their own right side
Check for
Symmetry
Deformities
Fractures
Masses
Calcifications
Lytic lesions
Check for
Cardiomegaly
Mediastinal and Hilar
contours
Trachea- upper med.
Apex of heart- lower med.
Check sharpness of
borders
Right is normally
higher than left
Check for free air,
gastric bubble, pleural
effusions
>1.5 cm - normal
< 1.0 cm- flat diaphragm
To help you
determine
abnormalities and
their location…
Use silhouettes of
other thoracic
structures
This is chest radiograph, PA view with normal
exposure, no rotation and without any apparent
bony abnormality. Trachea is placed centrally & lung
fields are clear with normal broncho-vescicular
markings. Cardiovascular silhouette is within normal
limits with normal cardiothoracic ratio. Mediastinum,
costo-phrenic, cardio-phrenic angles, dome of
diaphragm & soft tissue shadow within normal limits.